Three years later, in the midst of a massive drug war that’s taken more than 11,000 lives and brought the US and Mexico into closer and more costly cooperation, the initiative has quietly become law. And there’s hardly a peep.

Now not just marijuana, but cocaine, LSD, and heroin will be tolerated for personal and limited use. That means about four joints, or half a gram of cocaine, or 50 milligrams of heroin. Bigger quantities, sales, and public consumption are still strictly forbidden.

Officials here say the aim is to free up both resources and jail space so that authorities can focus efforts on big-time traffickers wreaking havoc in Mexico. "This frees us from a flood of small crimes that have saturated our federal government and allows the authorities to go after big criminals," said Bernardo Espino del Castillo, who works in the attorney general's office in Mexico.

It also focuses on rehabilitation for repeat drug users, making treatment mandatory for abusers. As we reported earlier this year, the number of addicts in Mexico has grown in just six years by more than 50 percent, from 300,000 to 465,000, according to government statistics.

The law now puts Mexico in a new league of leniency when it comes to drug use. Only Portugal has also legalized a wide range of drugs, Allen St. Pierre, executive director of Norml, a group seeking to legalize marijuana use in the US, told The Houston Chronicle.

Mexico seemed to anticipate a strong reaction from the US, not unlike the one it received in 2006, when President Vicente Fox’s initiative failed.

"This is not legalization, this is regulating the issue and giving citizens greater legal certainty," said Mr. Espino del Castillo. In other words, this is not an effort to draw back tourists – scared away by swine flu and violence – interested in experimenting with meth.

But so far the US has been quiet. During a July visit, US drug czar, Gil Kerlikowske, said he would take a "wait-and-see" approach if the law passed.

If US officials were to come down heavily on Mexico, it would be a departure from the praise that has come at every opportunity regarding the fight that Mexico is waging. "We know that Mexican law enforcement authorities are continuing their efforts to target drug traffickers," Department of Justice spokeswoman Laura Sweeneysaid Friday. "Our friends and partners in Mexico are waging an historic battle with the cartels, one that plays out on the streets of their communities each day."

Will the US now follow suit? Highly unlikely. But the new law in Mexico will definitely provide fuel to groups trying to reform US laws, particularly on marijuana use.